Lighting fixture



1943- H. ROWLAND- LIIGHTING FIXTURES Filed Feb. 4, 1941 INVENTOR f/ommo Ramp/v0 ATTORNEY Patented Aug. 17, 1943 UNITED STATES PATENT .oFFICE LIGHTING FIXTURE Howard Rowland, Chicago, 111., assignor to Electrical Testing Laboratories, New York, N. Y., a V corporation of New York Application February 4, 1941, Serial N 377,291

Y 4 Claims. (01. 240 -78) 2 The present invention relates to lighting fixtures and particularly to improvements infixtures of the type which employs a bi-post lamp and bi-post socket.

Where bi-post lamps and sockets areused in the usual pendent position there is a tendency for the socket and adjacent parts to heat excessively. This arises from the high currents which must be handled with consequent high resistance losses in conducting parts and contacts,

and from the heating of the socket by theconvection stream rising from the small diameter lamp itself. Tests of 1,000 watt equipment have indicated that with the lamp and socket alone in open air at ordinary room temperatures there may be temperatures of the order ,of 420. F. to 480 F. at the prong clips with from 340 F. to 370 F. at the wire binding screws.

As it is necessary for reasons of appearance to conceal the socket and wiring some form of a socket cover is usuallyemployed. The usual form of enclosing husk or socket cover used with screw base sockets and lamps wasfadopted by numerous manufacturers and experience. has proven that such arrangements were generally unsatisfactory. Socket temperatures 'rose considerably-in typical, cases prong clip andloind v ing wire screw temperatures in excess of 100 F. higher than open air conditions 'would be found, and where the same lamp and socket were used. Operation at these excessively high temperatures causes the contacts to deteriorate and is likely to bring about an early failure of the socket. The higher prong clip temperature is of course transmitted to the wire at the point 1 of contact making it necessary to use more expensive wire than would otherwise be required.

The present invention contemplates improvements in the construction of lighting vfixtures of the type employing bi-post sockets and lamps whereby the socket parts may be kept at mate- 'rially lower temperatures than with, the common Figures 3 and 3a are fragmentary sectional views at a more enlarged scale;

Figures 4: and 5 are diagrammatic sectional views of modified forms oi construction; and

Figure 6 illustrates a typical prior art construction used for comparative tests.

In the customary or known form of construction of Figure 6 the usual bi-post socket S with yoke Y and carrying a bi-post lamp L are secured in the usual way to a hanger H. The socket S isreceived in a metal socket cover or husk C of somewhat larger diameter than the socket and extending slightly below the socket. It may have ventilation holes at the top. Sheet metal louver rings R1 and R2 are alsoprovided to shieldv the upperpart of the lamp L. When such equipment with 1,000 watt lamp and the usualopen topped indirect lighting bowl was operated the average clip contact rise above room temperature was 490 F This temperature is higher than the contacts should be expected to carry. I

,The construction shown in Figures 1, 2 and 3 illustrate an arrangement of parts in which tests showed a reduction of temperature rise of the order of 160 F. bringing the temperature of the clip contacts in the concealed and housed socket below what they. would have been had the socket and lamp been operated in open air v ,The socket S, lamp L and hanger H may be the same as'before. The lamp has the usual posts Iii-H! adapted to pass through and interlock with the usual supporting springs II and enter the usual clip contacts l2. The clip contacts are carried on terminal straps l3 and binding screws l4 connect these straps to wires l5.

The socket S is received in a tube 20 which preferablyv fits Very closely about the socket so that heat is readily conducted away from the socket. The lower edge of the tube is even with the lower edge of the socket and the tube extends above the socket. In order to keep dust ofi the top of the socket the tube is closed at the top and a convenient form of construction is to provide the tube with a conical top 2| adapted to engage a flange 22a of a tube 22 disposed about the hanger H. The tube 20 hangs from this support.

The lower end of tube 20 is flanged outwardly as indicated at 23 and this flange supports an upwardly and outwardly flaring air deflector 24. This may have an angle of about 30 with the vertical and a diameter about twice that of the socket. The flange 23 is notched at 23' and a number of straps 25 extend downwardly alongside the lamp. These straps support two louver or baffle rings 26 and 21. These rings extend from close to the lamp surface upwardly and outwardly so as to deflect the convection stream away from the fixture axis. These bafile rings are cones with a common apex at the light cen ter L. C. They therefore present the minimum obstruction to the passage of radiant heat and direct light from the source, at the same time screening the top of the lamp. The lower bafile ring is notched at 28 to receive rods 29 adapted to supportabowl 30;

In Figure 3a the socket is shown as having a lower clamping ring I6 of larger diameter than the standard clamping ring I! of Figure 3. It.

assists in conducting heat awayyfrom the topof the lamp.

Figure 4 shows diagrammatically an arrange:

ment in which the air defiector'3l and louver rings 32 and 33 are the same as the correspond-' ing parts of Figures 1 and 2. The tube 34 which receives the socket S is longer than the cylindrical part of tube 213, Here the top of the tube is shown as open. With'this arrangement about the same temperatures are observed.

Closing the top of 2B or of 34 or of 3! and has been found to bring about higher tempera tures than with these parts open, but temperatures substantially below those produced in the customary construction.

Figure shows diagrammatically an arrangement in which the socket is received in a long cylindrical tube 35 with air deflector 36 similar to air deflector 24. The battle or louver rings 3'! and 38 are arranged like R1 and 32, Figure 6. The temperature conditions inthis arrangement are slightly higher than those in the arrangement of Figure 2, and there is some loss and redistribution of light.

In use the improved fixtures shown herein present an attractive appearance as the louvers and air deflector have pleasing lines. The light 1. In a lighting fixture, a pendent bi-post lamp socket, a oi-post lamp therein, a socket enclosing tube fitted closely about the socket extending "heated by the lamp is kept away from the tube and socket, and upwardly and outwardly diverging conical baflle rings below the air deflector and ing to direct heated air intercepted thereby out- .wardly and keep it away from the conical air deflector to reduce the heating of the socket conoutput is not sensibly affected, but the distribution is slightly altered owing to reflection'of the zone of direct light which falls'cn the air deflector.

It is apparent that, within the 'scope of the invention, modifications and difierent arrangements may be made other than is herein disclosed, and the present'disclosure'is illustrative merely. the invention comprehending all'variefi 'tions thereof. 1

What is claimed is:

tacts and lamp terminals.

2; A lighting fixture such as claimed in claim 1,wherein the baflle rings converge toward the I light center of the lamp so as to intercept the minimum of direct light and radiant heat.

3. A lighting fixture comprising a pendent support, a bi-post lamp socket secured to the lower end of the support, a bi-post lamp in the socket, a socket enclosing tube fitted closely about the socket, means forsupporting the tube from the pendent support with its lower end substantially even with the bottom of the socket, an upwardly and outwardly flaring conical air deflector extending to and carried by the lower end of the tube, said deflector having its lower. endsubstantially even with the bottom of the socket'and in close contact with the tube, straps extending downwardly from the tube and about the upper part of the lamp, upwardly and outwardly flaring conical baffle rings secured to the straps, the

rings and deflector acting to direct heated air intercepted thereby outwardly and k ep it away from the socket enclosing tube to reduce the heating of the socket contacts and lamp terminals, and an upwardly opening lamp receiving bowl supported from the straps with its upper edge substantially level with the lowermost ring.

4. A- lighting fixture such as claimed in claim 3, wherein the socket is carried on a yoke, the

upper end of the tube converges inwardly and the tube supporting means includes a sleeve about the pendent support and extending from the yoke to the narrowed end'of the tube.

HOWARD ROWLAND. 

